I think the balls deep thing is a clue, but it’s not the way you think it is.
If you can last more than a few minutes anyhow, you are ready to try this:
Go in slowly and work your way in all the way - BALLS DEEP.
Then stop. Then take it easy. if you can go slow enough to get used to the fantastic sensations, you should find that after 5 minutes, you can last as long as you like - as long as you don’t speed up.
Having talked to quite a few “short fuse” guys, what I found was that there was a part of their personality that was in a hurry. So they went at it too fast, got too excited and did not realise that all the friction was rapidly taking them to the point of no return.
What I found when I trained myself to be a “long laster” was that going in deep could actually help me last longer if I went in deep and rested in that position for a while. I felt like the feeling of clamping at the base of my cock seemed to slightly anaesthetise it - just enough, that I was able to go faster after a short stay in this position.
In any case, the trick is to start each session slow until you get used to it - which takes about 5 minutes. Then you can speed up. Why not try it and report back?